A Dog Could Be Your Child’s Immune System’s Best Friend
A new study from the University of Alberta shows that babies who grow up around a pet are healthier than those who do not.
This is not, however, the old story about the unconditional love of pets and the exercise children get by having a pet around. It is more complicated and a lot more amazing than that.
The study, which covers two decades of work by Anita Kozyrskyj, a University of Alberta epidemiologist, looked at fecal samples from infants who took part in the Canadian Healthy Infant Longitudinal Development Study. It concluded, among other things, that babies who are around a pet (70% of which were dogs in the study) have lower rates of asthma.
Kozyrskyj and Hein Min Tun, the co-author of the study and a University of Alberta post-doctoral fellow, took the investigation to yet another level by digging deeper. Kozyrskyj, one of the world’s pre-eminent researchers on gut microbes (micro- organisms that live within the human digestive tract and that have been linked to deeper understandings of cancer and other diseases), wanted to understand what might be different in the gut microbes of babies exposed to a pet when very young. What she, Hein Min Tun and her team of 11 other researchers found was that, for babies exposed to a pet while still in the womb and up to three months after birth, the bacterial types Ruminococcus and Oscillospira show up in significantly higher quantities in those babies’ guts. The first of these is associated with reduced childhood allergies. The second is related to reduced obesity.
Other analyses showed that it is not just the babies who benefit from having a pet around at the right time. For expectant mothers, the data showed that mothers-to-be who are around a pet have a reduced likelihood of transmission of vaginal GBS (also known as Group B Strep) during birth. This type of strep causes pneumonia in newborns and
is most often handled by giving mothers antibiotics during their pregnancy.
How this all works is still unclear. With the common thread being the presence of a pet, one theory is that dirt and bacteria carried on a pet and even in its own gut microbes are somehow being transmitted to the expectant mother and the baby. It could be by sheer proximity or by direct pickup and contact, such as by touch or contamination of the pet.
Details of the study also suggest that two things are going on at the same time. There is first what the scientists refer to as “a healthy microbial exchange” between the microbes in and around the baby and in and around the pet, some of which come from inside the animal and some of which are tracked in from the surroundings. The second involves how the baby’s own immune system responds to those microbes by building up its own antibodies.
When the baby is in the womb, such as in the case of vaginal GBS, both the expectant mother and the fetus benefit from the same exposure at the same time through a likely very similar process. Besides that this appears to lower the risk of Group B Strep at birth, it could also minimize the need for the normal antibiotics administered to the mother prior to childbirth. That is important not just for the mother but also because it appears that giving those antibiotics prior to birth tends to reduce the presence of certain important, “good” gut microbes in the baby-to-be.
The researchers have speculated that some eager pharmaceutical companies are looking to cash in on this research and create the equivalent of a “dog in a pill” or an injection to recreate the same effects. That is unfortunately probably true. And they will likely come up with some fancy trademarks, heavy advertising and other ways to convince doctors to prescribe it to their patients and prospective patients to demand it.
Fortunately for humanity and our pets, that scenario will thankfully never come to pass. Because, besides the unique nature of the environment, the constant microbial exchange between babies and the pets around them and the many unknowns in how the immune system and gut work, somehow “taking a pill” seems a way too sterile approach to what appears to be one more of life’s happy accidents.
And besides that, when was the last time you could teach a pill to fetch, roll over, jump up on your lap or lick your face?